<!DOCTYPE html>
<html lang="zh">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        . {
            margin: 0;
            padding: 0;
        }

        /* 添加图片 */
        .box img {
            width: 100%;
            height: 100%;
        }

        /* 定义盒子，赋予面积 */
        .box {
            position: relative;
            width: 444px;
            height: 320px;
            margin: 100px auto;
        }

        /* 盒子阴影部分 */
        .shadows {
            position: absolute;
            top: 0;
            display: none;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.5) url(images/arr.png);
            background-repeat: no-repeat;
            background-position: center;
        }

        .box:hover .shadows {
            display: block;
        }
    </style>
</head>

<body>
    <div class="box">
        <img src="images/tudou.jpg" alt="">
        <a href="">
            <div class="shadows"></div>
        </a>
    </div>
</body>

</html>